The present invention relates to an optical pickup guide mechanism, and more particularly, to the optical pickup guide mechanism including a chassis made of a resin material, a main shaft attached to the chassis and a sheet metal frame attached to the chassis, instead of a sub shaft. The main shaft and the sheet metal frame guide an optical pickup in a straight line path.
FIG. 5 is a schematic top view illustrating an exemplary configuration of a related-art guide mechanism. The related-art guide mechanism includes a main shaft 2 and a sub shaft 3 which are metal rods mounted on a chassis 1, and thus an optical pickup 4 is guided by the main shaft 2 and the sub shaft 3 so as to move in a straight line path A. In addition, the chassis 1 includes a turn table 5 for rotating an optical disk.
In the related-art guide mechanism shown in FIG. 5, the main shaft 2 serves to move smoothly the optical pickup 4, and the sub shaft 3 serves to suppress shaking in the movement of the optical pickup 4. In FIG. 5, the sub shaft 3 employs the same metal rod as the main shaft 2.
In the other related-art guide mechanism, an edge of the chassis is used for guiding the optical pickup instead of the sub shaft (for example, see Patent Document 1 and Patent Document 2). FIG. 6 illustrates a schematic perspective view of such a related-art guide mechanism. In the related-art guide mechanism shown in FIG. 6, a side wall 11 of an opening formed on the chassis 1 serves as the sub shaft, and the optical pickup 4 includes a recessed guide groove portion 41 which is engaged with the side wall 11 so as to freely slide on the side wall 11.
Additionally, in still another related-art guide mechanism, a transporting unit of an optical pickup is configured such that a guide member formed of a sheet metal and fixed on the chassis by a screw serves as the sub shaft (for example, see Patent Document 3).    Patent Document 1: Japanese Utility Model Publication No. 4-49320A    Patent Document 2: Japanese Patent Publication No. 2002-50055A    Patent Document 3: Japanese Patent Publication No. 7-235063A
When the metal rod is used as the sub shaft 3 as described in the related-art guide mechanism shown in FIG. 5, a cost of the entire guide mechanism is increased due to a high cost of the metal rod.
From this viewpoint, when the side wall 11 which is the edge of the chassis is used as the sub shaft, there is no need to employ the expensive rod. However, in such a case, it is necessary to employ the sheet metal for the entire chassis in order to suppress a decrease in guide performance caused by abrasion of the side wall 11, and thereby the cost of the entire guide mechanism increases. If the chassis 1 is made of the resin material instead of the sheet metal, the guide performance may decrease due to the abrasion of the chassis 1.